Question
The average age of a group of 15 students is 20
years. Two persons of age 50 years and 35 years, left the group and 2 persons of age 50 years and 80 years, joined the group. Find the new average age of the group.Solution
Required average = {(15 × 20) – 50 – 35 + 50 + 80}/15 = 23 years
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